Re: [RFC PATCH v2 1/9] vfio/pci: split vfio_pci_device into public and private parts

From: Yan Zhao
Date: Sun Feb 09 2020 - 19:44:02 EST


On Sat, Feb 08, 2020 at 03:48:31AM +0800, Alex Williamson wrote:
> On Thu, 30 Jan 2020 21:09:56 -0500
> Yan Zhao <yan.y.zhao@xxxxxxxxx> wrote:
>
> > split vfio_pci_device into two parts:
> > (1) a public part,
> > including pdev, num_region, irq_type which are accessible from
> > outside of vfio.
> > (2) a private part,
> > a pointer to vfio_pci_device_private, only accessible within vfio
> >
> > Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> > Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
> > ---
> > drivers/vfio/pci/vfio_pci.c | 209 +++++++++++++++-------------
> > drivers/vfio/pci/vfio_pci_config.c | 157 +++++++++++----------
> > drivers/vfio/pci/vfio_pci_igd.c | 16 +--
> > drivers/vfio/pci/vfio_pci_intrs.c | 171 ++++++++++++-----------
> > drivers/vfio/pci/vfio_pci_nvlink2.c | 16 +--
> > drivers/vfio/pci/vfio_pci_private.h | 5 +-
> > drivers/vfio/pci/vfio_pci_rdwr.c | 36 ++---
> > include/linux/vfio.h | 7 +
> > 8 files changed, 321 insertions(+), 296 deletions(-)
>
> I think the typical solution to something like this would be...
>
> struct vfio_pci_device {
> ...
> };
>
> struct vfio_pci_device_private {
> struct vfio_pci_device vdev;
> ...
> };
>
> External code would be able to work with the vfio_pci_device and
> internal code would do a container_of() to get access to the private
> fields. What's done here is pretty ugly and not very cache friendly.
> Thanks,
>
got it, it's much better!
will change it. Thanks!

Yan